Molecular Identification of Cryptic Cysticercosis: Taenia spp. in Wild and Domestic Intermediate Hosts in Kazakhstan

Cysticercosis in wild and domestic ungulates, caused by the larval metacestode stages of Taenia hydatigena and Taenia multiceps (formerly known as Cysticercus tenuicollis and Coenurus cerebralis, respectively), is a widespread parasitic disease and poses a significant concern worldwide, particularly in endemic regions. Although Taenia species have been extensively studied globally, their epidemiology and genetic diversity in Kazakhstan remain poorly understood. In this study, wild (roe deer, red deer, moose) and domestic (cattle, sheep) ungulates, serving as intermediate hosts for Taenia spp., were examined for cysticerci in muscle tissues and internal organs. Phylogenetic analysis and pairwise nucleotide variation assessments of the cox1 and nad1 genes were conducted. An overall prevalence of 5.2% was recorded among 1370 ruminant carcasses (cattle = 773, sheep = 563, roe deer = 25, moose = 9), with infection rates of 0.6% in cattle, 1.1% in sheep, 8.0% in roe deer, and 11.1% in moose. Cattle, sheep, and moose were infected with T. hydatigena, while roe deer were infected with T. multiceps. DNA sequence analysis of all isolates revealed four nad1 gene haplotypes for T. hydatigena, with Hap_3 being the most common (10 isolates). Phylogenetic analysis showed that T. multiceps isolates from roe deer clustered within the clade defined by the reference sequences for this species. This study provides important baseline data on the prevalence and genetic variation in T. hydatigena and T. multiceps in Kazakhstan and lays the groundwork for future research on the epidemiology and population genetics of Taenia species in the region.